Abstract

COMBATT CABALLERO, Enrique Miguel; ALVAREZ V, Víctor Hugo  and  DOS SANTOS, Andrés Ferreira. Determination of sulphate by turbidimetry in acid sulpahte soil. Acta Agron. [online]. 2014, vol.63, n.1, pp.42-47. ISSN 0120-2812.  https://doi.org/10.15446/acag.v63n1.31922.

The objective has been compare three surfactants in dosage of sulfur available in acid sulphate soils. Were collected 12 Soil samples in the State of Espírito Santo - Brazil and in Córdoba -Colombia. To evaluate the effect of surfactants in the preparation of 20 ml suspension of reading, has been selected 5 ml of suspension and was added 15 ml of working reagent. The 15 ml had 0.8 g of BaCl₂ and the treatments were: 8 mg gum arabic, or 0.15 ml Tween, or 30 mg polyvinyl alcohol.In addition to this, was applied 0.15 ml of HNO₃/lt at a concentration 50mmol, in order that pH of the reading suspensions had been between 3 and 3.3. The sulfur was extracted with Ca (H₂PO₄)₂, 500 mg/lt P in HOAc 2 mol/lt and determined by turbidimetry. For comparison of the surfactants were used three replicates by dosage and the data were analyzed by 't' test, to comparison between two methods was applied statistical test of identity of two methods. It can be concluded that the surfactant gum arabic showed the best performance in operational terms, but it is also possible to use polyvinyl alcohol for the quantification of S-SO₄^2-.

Keywords : Available sulfur; barium sulfate; gum Arabic; surfactants.

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